The overall objective of the total project is to study how the central nervous system integrates reflex reactions through the autonomic nervous system and neuroendocrine system in the maintenance and adjustment of the body. Our immediate objectives are three: 1) Reciprocal and non-reciprocal patterns of cardiac sympathetic and vagal activities previously found in our studies will be correlated with changes in responses of the cardiovascular system. We wish to find the functional significance of varied patterns of discharges in the autonomic nerves. 2) Studies of the control of neurosecretory neurons concerned with vasopressin production and release will be completed. Effects of olfaction and pathways of olfactory input to neurons in the supraoptic and paraventricular nuclei will be fully investigated. The role of neurosecretory neurons of these hypothalamic nuclei in muscle exercise is another project to be completed. 3) A study of viscero-visceral reflexes on somato-autonomic integration will be carried out as a pilot project. In all projects we will employ any necessary electrophysiological techniques available: intra- and extracellular recordings from neurons, single and multifiber recordings from autonomic and somatic nerves, stimulation of receptors and nerves by natural as well as artificial means. We measure hemodynamic changes extensively. We will pay special attention to maintain "normal" conditions; the blood gas tensions, blood pH, body temperature, etc. will be rigidly controlled. This is particularly important for our study, since the autonomic reflex response, specifically vagal activity, is extremely sensitive to a slight change in e.g., blood gas concentrations.